System and method for out-of-line real-time in-service performance measurement

Abstract

A system for out-of-line testing of performance of a network, comprising a multiplexer at an input to the network; a demultiplexer at an output from the network; the multiplexer further comprising a traffic generator to insert synthetic traffic, and a first switch to accept an incoming customer traffic stream and join the incoming customer traffic stream with a synthetic traffic stream to form a total traffic stream, the total traffic stream fed to the input to the network; and the demultiplexer comprising a second switch to receive the total traffic stream from the output of the network, and separate the total traffic stream into the synthetic traffic stream and the customer traffic stream, and a traffic analyzer to analyze the separated synthetic traffic stream.

What is claimed is: 
     
       1. A system for out-of-line testing of performance of a network, comprising:
 a multiplexer at an input to the network; 
 a demultiplexer at an output from the network; 
 said multiplexer further comprising
 a traffic generator to insert synthetic traffic stream out-of-line, and 
 a first switch to accept an incoming customer traffic stream comprising a plurality of customer packets and determine the presence of one or more inter-packet gaps between said customer packets and inserting said synthetic traffic stream into said one or more inter-packet gaps when the inter-packet gap is longer than a threshold duration to form a total traffic stream, said total traffic stream fed to said input to said network; 
 
 and said demultiplexer comprising a second switch to receive said total traffic stream from said output of said network, and separate said total traffic stream into the synthetic traffic stream and the customer traffic stream, and 
 a traffic analyzer to analyze said separated synthetic traffic stream. 
 
     
     
       2. The system of  claim 1 , further wherein said first switch generates a copy of said customer traffic stream. 
     
     
       3. The system of  claim 2 , further comprising removing said copy of said customer traffic stream. 
     
     
       4. The system of  claim 3 , further wherein said removing is performed by the traffic generator. 
     
     
       5. The system of  claim 1 , wherein said network is an Ethernet network. 
     
     
       6. The system of  claim 1 , wherein said traffic analyzer determines one or more metrics. 
     
     
       7. A method for out-of-line testing of performance of a network, comprising:
 multiplexing, using a multiplexer at an input to the network, an incoming customer traffic stream comprising a plurality of customer packets and a synthetic traffic stream generated out of line to form a total traffic stream; 
 said multiplexing comprising accepting the incoming customer packets, determining the presence of one or more inter-packet gaps between said customer packets, inserting said synthetic traffic stream out-of-line into said one or more inter-packet gaps when the inter-packet gap is longer than a threshold duration to form a total traffic stream, and feeding said total traffic stream to said input to said network; 
 demultiplexing, using a demultiplexer at an output from the network, said total traffic stream into said customer traffic stream and said synthetic traffic stream, 
 said demultiplexing comprising
 receiving said total traffic stream from an output from said network, 
 separating said total traffic stream into the synthetic traffic stream and customer traffic stream, and 
 analyzing said separated synthetic traffic stream. 
 
 
     
     
       8. The method of  claim 7 , further comprising copying said customer traffic stream. 
     
     
       9. The method of  claim 8 , further comprising removing said copy of said customer traffic stream. 
     
     
       10. The method of  claim 9 , wherein said inserting of generated synthetic traffic stream, and said removing of said copy of said customer traffic stream is performed by a traffic generator. 
     
     
       11. The method of  claim 7 , wherein said network is an Ethernet network. 
     
     
       12. The method of  claim 7 , wherein said analyzing comprises determining one or more metrics.